• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.232-242
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• 2015

For stealth performance consideration, many UAV designs are adopting tailless lambda-shaped configurations which are likely to have unsteady dynamic characteristics. In order to control such UAVs through automatic flight control system, more accurate estimation of dynamic stability derivatives becomes essential. In this paper, dynamic stability derivatives of a tailless lambda-shaped UAV are estimated through numerically simulated forced oscillation method incorporating dynamic mesh technique. First, the methodology is validated by benchmarking the CFD results against previously published experimental results of the Standard Dynamics Model(SDM). The dependency of initial angle of attack, oscillation frequency and oscillation magnitude on the dynamic stability derivatives of a tailless UAV configuration is then studied. The results show reasonable agreements with experimental reference data and prove the validity and efficiency of the concept of using CFD to estimate the dynamic derivatives.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.422-429
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• 2011

Dependence of radical and ion density on electron density and temperature is numerically investigated for $Cl_2$/Ar, $CF_4$, $CF_4/O_2$, $CF_4/H_2$, $C_2F_6$, $C_4F_8$ and $SF_6$ discharges which are widely used for etching process. We derived a governing equation set for radical and ion densities as functions of the electron density and temperature, which are easier to measure relatively, from continuity equations by assuming steady state condition. Used rate coefficients of reactions in numerical calculations are directly produced from collisional cross sections or collected from various papers. If the rate coefficients have different values for a same reaction, calculation results were compared with experimental results. Then, we selected rate coefficients which show better agreement with the experimental results.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.3
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• pp.64-70
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• 2004

Korean and Japanese have same structure of sentences because they belong to same family of languages. So, The transfer driven machine translation is most efficient to translate each other. This paper introduce a method which creates a transfer dictionary for Token Based Transfer Driven Koran-Japanese Machine Translation(TB-TDMT). If the transfer dictionaries are created well, we get rid of useless effort for traditional parsing by performing shallow parsing. The semi-parser makes the dependency tree which has minimum information needed output generating module. We constructed the transfer dictionaries by using the corpus obtained from ETRI spoken language database. Our system was tested with 900 utterances which are collected from travel planning domain. The success-ratio of our system is $92\%$ on restricted testing environment and $81\%$ on unrestricted testing environment.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.8-14
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• 2006

The object of this study was to investigate the carbonization of Quercus variabilis wood samples in pyrolysis system at temperature ranging from 250 to $740^{\circ}C$ to contribute to the knowledge of wood carbonization mechanism. Volume of wood sample decreased with increasing the carbonization temperature, and checks were developed along with radial direction. Weight loss increased with increasing carbonization temperature. During carbonization, tangential direction showed higher shrinkage of vessel diameter than radial direction. SEM observation indicated that the cell walls in wood fibers and parenchyma cells presented the layering structure at $250^{\circ}C$ and $300^{\circ}C$. However, the cross section of cell walls at $340^{\circ}C$ and over showed an amorphous- like structure without cell wall layering. X-ray diffraction presented that the cellulose crystalline substance was still remained in carbonization temperature at $340^{\circ}C$, but it was not detected at $540^{\circ}C$ and over.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.704-709
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• 1994

The $(LaS)_xCrS_2(x \approx 1.20$) of the incommensurate misfit layer was systhesized from reactant mixture of$La_S_3$,Cr and S at 1273K. Powder X-ray diffration of $(LaS)_xCrS_2(x \approx 1.20$) was indexed as a complex structure consisted with a monoclinic LaS-sublattice, a triclinic $CrS_{2}$-sublattice and their superlattice. The temperature dependence of sublattice dimension was investigated by the X-ray diffraction analysis at low temperature. The magnetic susceptibility of $(LaS)_xCrS_2(x \approx 1.20$) was measured between 77K and room temperature using a Faraday balance method. $(LaS)_xCrS_2(x \approx 1.20$) was paramagnetic on a $\sigma$-H plot at room temperature. The observed effective magnetic moment( p dr) was in fair agreement with the value calculated by spin-only contribution for $Cr^{3+}$ and spin and orbital contribution for $La^{3+}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2993-3002
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• 2015

INCOTERMS 2010 apply to the International Trade Contract for the last 5 years. The export trade condition and the document type for last 10 years was researched to analysis of the practical problems of INCOTERMS 2010 application. The result of the research; First, several rules which are against the official INCOTERMS 2010 rules are used. Second, the conventional rules like FAS FOB, CIF and CFR which are used for the ocean and inland transportation are applied without any changes. Third, the issue of the time of delivery(transfer of ownership) at the CPT and CIP affects not to activate these two rules. Fourth, the frequency of the DAT use is low. Because, the terminal designate is hard at the point of the contract and the terminal is changeable during the transport. According to these issues, the active publicity campaign is needed for the INCOTERMS 2010. And, the analysis of the terms and the solution of conflict are also needed.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.436-443
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• 2014

This study was begun on the premise that architecture which has the definite disposition for survival even in the urban, social structure of that uncertainty and constructs specialty is biomorphic architecture. This study was organic philosophy background analysis of Biomorphic architecture occurrence, through meaning inherent analysis in Biomorphic architecture, which going to be deployed atypical and new shape one. Biomorphic architecture is organism shape of structure of autonomous survival, which is shaped the potential of biological phenomena. Theoretical analysis of the Biomorhpic architecture characteristic was analysed. Factor in the occurrence of Biomorphic architecture based on an objective analysis of the research is characteristic analysis. Which is reason as the 'create', the science of complexity and emergent System. The generation causes of biomorphic architecture are an organic philosophy. Biomorphic architecture makes the realization of simile form using the procedural principle represented by in natural phenomena.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6105-6110
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• 2012

Smart devices have made our daily life more intelligent and provided convenient life styles in which advanced interface and high speed LTE enable us to have proliferation of empirical Apps. This research has analyzed and evaluated Unstructured data from the users who experienced 'Hair Style Magic Mirror App' by focusing on emotional information. Further this study suggests some directions that the application development industry should take in the near future. The findings through Chi-Square analysis indicate that the application has not affected the overall satisfaction of the consumers; consumers received higher satisfaction in paid version of applications than free versions. Emotional Information analysis shows that users value the practicality of each application the most. Thus, the application developers should focus on practicality and sensitivity side corresponding to the demand of consumers.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1316-1323
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• 2005

Most tunnel lining material which has been used in the domestic is a concrete. But many problems as the construction period, the cost, and the crack occurrence for the design, construction, and management were happened in the concrete lining. For this reason, many research institutes like the Korea Highway Corporation recognize the necessity of an alternate material development and grow on the interest for that. So in this study, the behaviour characteristics for the application of the Corrugated Steel Plate Lining in cut-and-cover tunnel are evaluated as several conditions for the backfill height, the cutting slope, and the relative density of backfill soil are changed. In addition, through using that conditions, CHBDC(2000, Canadian Highway Bridge Design Code) is evaluated if it could be applied to the design by comparing with the numerical analysis results. As the behaviour characteristics of the Corrugated Steel Plate Lining by CHBDC and the static numerical analysis are analyzed, both the methods show the same linear increases of the compressive stress according to the increase of the backfill height. The CHBDC of the dead load condition has very similar tendency by comparing with the result of the static numerical analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.104-112
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• 2002

In this paper, it is suggested that the selection method of parameter of Power System Stabilizer(PSS) with robustness in low frequency oscillation for Thyristor Controlled Series Capacitor(TCSC) using Geletic Algorithm(GA). A TCSC meddle consists of a stories capacitor and a parallel path with a thyristor valve and a series inductor. Also in in parallel, as is typical with series capacitor applications, is a metal-oxide varistor(MOV) for overvoltage protection. The proposed PSS parameters are optimized using GA in order to maintain optimal operation of TCSC which is expected to be applied in transmission system to achieve a number of benefits under the various operating conditions. In order to verify the robustness of the proposed method, we considered the dynamic response of angular velocity deviation and terminal voltage deviation under a power fluctuation and rotor angle variation.